fix(discover,learn): encode Windows drive colon in project path slug

[ALCHEMISTK]

Summary

Fixes #2367 — on native Windows, rtk discover and rtk learn always scanned 0 sessions without --all/--project, because encode_project_path() kept the drive colon (C:\Users\foo → C:-Users-foo) while Claude Code's project slug encodes it to a dash (C--Users-foo). The cwd-derived default filter could therefore never substring-match the real ~/.claude/projects/ directory name.

Changes

• Add ':' to SANITIZED_CHARS in encode_project_path() (same treatment fix(provider): sanatize more chars when encoding claude code project pathes #2172 gave spaces/brackets/non-ASCII)
• Correct the doc-comment example (C:\Users\foo\bar → C--Users-foo-bar)
• Fix test_encode_project_path_windows, which pinned the wrong expectation
• Add test_encode_project_path_windows_drive_colon regression test

Both discover and learn build their default filter from this function, hence the dual scope.

Verification

• cargo test: 2149 passed, 8 ignored (full suite, Windows 11)
• Real-world before/after on Windows 11 + Claude Code, rtk 0.42.3 base:
  • before: rtk discover → Scanned: 0 sessions (last 30 days), 0 Bash commands
  • after (encoder parity, validated via the equivalent --project substring): Scanned: 504 sessions (last 30 days), 3382 Bash commands

Notes

• Unix paths containing : are legal but Claude Code encodes them to - there too, so the change strictly improves parity on all platforms.
• Complementary to fix(discover,learn): default to scanning all projects instead of encoding CWD #2228 (default to --all): that PR masks the no-flag symptom; this one fixes the encoder so cwd-scoped filtering actually works on Windows.

🤖 Generated with Claude Code

[CLAassistant]

All committers have signed the CLA.

[ALCHEMISTK]

done

[KuSh]

Thanks for tracking this down. The drive-letter colon is now sanitized on develop: #2952 (merged 2026-08-13) added ':' to SANITIZED_CHARS in encode_project_path, fixed the doc-comment example to C--Users-foo-bar, and updated test_encode_project_path_windows to the same expectation, so the cwd-derived project filter matches Claude Code's real folder name on Windows. The only piece here that is not on develop is a second assertion of the same code path with a different drive letter. Closing as already fixed, but please comment or reopen if something in your setup is still not covered.